Morning/Daytime Breakfast Diet Advice

I am looking for some advice. I have started a new job that requires me to be up at 6am every morning. I am struggling with bloating and trapped wind in the morning and I am unable to go to the toilet first thing.
I have either a slice of toast or a croissant for breakfast with a glass of semi-skimmed milk. If I attempt to eat during the day I get bloating and extremely tired. I was thinking about protein shakes but I am worried about trapped wind. I do drink diet cokes but I am…